University of Tokyo associate professor Kei Ito is seen with textured paving blocks in new "cool" and "warm" colors, in Tokyo's Bunkyo Ward on Dec. 22, 2017. (Mainichi)

A research team at the University of Tokyo has designed new textured paving blocks that are not only easy to see for people with visual impairments, but that are also harmonious with the landscape.

Architect Kengo Kuma, who designed the new National Stadium being built for the 2020 Tokyo Olympics and Paralympics, and four domestic manufacturers helped develop the blocks with the university's Institute of Molecular and Cellular Biosciences. The team is aiming to commercialize the blocks by spring 2018, though it will not apply to patent the designs in hopes that they will be broadly and quickly adopted.

Guidelines issued by the former Ministry of Construction said the blocks should "basically be yellow," while the new barrier-free law implemented in 2006 simply demands they be a color that's easy to distinguish from the surroundings. In short, there is no concrete legal definition for what color the blocks have to be, and so designers have recently been eschewing the usual loud yellow in favor of gray, black or stainless steel blocks that better match the scenery.

However, textured paving blocks are important for people with weak eyesight, not just the blind. Critics have called the more understated blocks in Takayama, Gifu Prefecture, and the city of Niigata dangerous as they tend to melt into the background and are difficult to spot.

Enter Kei Ito, an associate professor of neurobiology at the University of Tokyo. Ito and his team researched how people with weak eyesight see pale yellow, which is more harmonious with the landscape. Results showed that greenish "cool yellow" and orange-tinged "warm yellow" are just as easy to make out even at dusk as conventional "yellow" blocks. The team also devised designs and ways of arranging the blocks to make it easier for wheelchairs and strollers to roll over them, such as rounding off the blocks' dot textures.

Ito said, "The blocks will help people to balance barrier-free needs with the scenery for the 2020 Tokyo Olympics and Paralympics," Ito said. Architect Kuma added, "It is much easier to match the new colors to buildings than the previous blocks. It was an eye-opening discovery. I absolutely want to help them (the new blocks) be broadly adopted."